Metric Conversion Chart
| US (inches) | Metric (millimeters) |
| 1/16 | 1.6 |
| 1/8 | 3.2 |
| 3/16 | 4.8 |
| 1/4 | 6.4 |
| 5/16 | 7.9 |
| 3/8 | 9.5 |
| 7/16 | 11 |
| 1/2 | 13 |
| 9/16 | 14 |
| 5/8 | 16 |
| 11/16 | 17 |
| 3/4 | 19 |
| 13/16 | 21 |
| 7/8 | 22 |
| 15/16 | 24 |
| 1 | 25 |
| 1-1/8 | 29 |
| 1-1/4 | 32 |
| 1-3/8 | 35 |
| 1-1/2 | 38 |
| 1-5/8 | 41 |
| 1-3/4 | 45 |
| 1-7/8 | 48 |
| 2 | 51 |
| 2-1/4 | 57 |
| 2-1/2 | 64 |
| 2-3/4 | 70 |
| 3 | 76 |
| 3-1/4 | 83 |
| 3-1/2 | 89 |
| 3-3/4 | 95 |
| 4 | 102 |
| 4-1/2 | 114 |
| 5 | 127 |
| 5-1/2 | 140 |
| 6 | 152 |
| 6-1/2 | 165 |
| 7 | 178 |